Various types of catalytic hydrocarbon conversion processes have found widespread utilization throughout the petroleum and petrochemical industries for affecting the conversion of hydrocarbons to different products. Often these conversion processes result in either the net production of hydrogen or the net consumption of hydrogen. Examples of net hydrogen-producing hydrocarbon conversion processes include catalytic reforming, catalytic dehydrogenation of alkylaromatics, and catalytic dehydrogenation of paraffins. Of these, catalytic reforming is one of the most widely employed.
Catalytic reforming of hydrocarbons is used by refiners for upgrading the octane rating of gasoline. In catalytic reforming, a hydrocarbon feedstock of, for example, C5 hydrocarbons to about C11 hydrocarbons, is contacted with a reforming catalyst to convert at least a portion of the heavier hydrocarbons to aromatic hydrocarbons to increase the octane content of gasoline. The catalytic reforming of the heavier hydrocarbons to produce a liquid reformate that contains C5+ hydrocarbons including aromatic hydrocarbons also produces significant quantities of valuable hydrogen and lighter hydrocarbons, such as liquefied petroleum gas (LPG) containing primarily C3 and C4 hydrocarbons, that form a hydrogen-, hydrocarbon-containing gas stream (e.g., net gas stream). Additionally, the hydrogen-, hydrocarbon-containing gas stream may also contain some unrecovered C5+ hydrocarbons. Some refiners currently separate hydrogen and liquefiable hydrocarbons, such as LPG and C5+ hydrocarbons, contained in a net gas stream using an elaborate and expensive sequence of vessels each performing a distinct unit operation for extracting and liquefying the C3+ hydrocarbons from the net gas stream. Refiners are looking for more efficient ways to maximize the recovery of hydrogen, LPG, and C5+ hydrocarbons from hydrogen-, hydrocarbon-containing gas streams.
Accordingly, it is desirable to provide apparatuses and methods for separating liquefiable hydrocarbons, such as C3+ hydrocarbons, from hydrogen-, hydrocarbon-containing gas streams produced, for example, from catalytic reforming of hydrocarbons. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background.